Oil combustion apparatus



may 1936- o c. scHRoEDE'R 2,039,937

0 IL COMBUST ION APPARATUS Filed Aug. 2, 1953 5 Sheets-Sheet '1 y 936. r o. c. SCHROEDER OIL COMBUSTION APPARATUS 5 Sheets-Sheet 2 Filed Aug. 2, 1933 y 1936- o. c SCHROEDER 1 on COMBUSTION APPARATUS Filed Aug. 2, 1955 5 sheets-sheet 3 Patented May 5, 1936 NITED STATES PATENT OFFICE OIL COMBUSTION APPARATUS Oscar C. Schroeder, Chicago, Ill.

Application August 2, 1933, Serial No. 683,372

17 Claims.

One of my objects is to provide in oil combustion apparatus of the type in which the combustion of the oil delivered from the center of the hearth takes place generally in the form of a ring at the outer peripheral portion of the hearth, improvements to the end that the apparatus may be started quickly into operation, complete combustion of the fuel will be effected; and maximum efiiciency will be obtained; and other objects, as will be manifest from the following description.

Referring to the accompanying drawings:

Figure 1 is a view in elevation of the lower portion of a furnace embodying my invention and comprising, as an element thereof, an oil burner assembly, certain portions of the structure shown being represented in sectional elevation.

Figure 2 is a plan view of a ring associated with the hearth, together with the clip devices for holding it in position,

Figure 3 is a broken perspective view of a portion of the ring of Fig. 2.

Figure 4 is a perspective View of one of the similar clip devices.

Figure 5 is a broken view in vertical sectional elevation of a portion of the furnace structure showing a modification of the outer portion of the hearth and the igniter means.

Figure 6 is a broken face view of the ring of Fig. 2.

Figures '7 and 8 are broken face views of modifications of the ring structure; and

Figure 9, a section taken at the line 9 on Fig. 8 and viewed in the direction of the arrow.

Referring to the particular construction shown, 10 represents a furnace, shown as of the hotwater-boiler type, having a combustion chamber II formed with a hearth portion of refractory material centrally apertured and supported on a centrally apertured plate 12, as forexample of metal, carried by the base l3 of the furnace.

The hearth portion shown and formed of any suitable refractory material, comprises a ringlike base portion l4 positioned fiatwise on the plate l2, an upstanding ring portion l5 resting at its lower end on the plate l2 and surrounding the ring l4, and a ring portion [6 positioned flatwise on the ring l4, but of smaller diameter than the latter to provide an annular space between the ring l6 and the ring [5.

t may be here said that in the assembling of the parts of the combustion apparatus the oil burner assembly hereinafter referred to is positioned at the lower end of the combustion chamber II and the plate l2 then applied to the position shown and the ring portions l4 and I5 cast in place, either at the same time or separately, in which latter case the portion last to be cast is cast before the other sets; in either case the base with its flange forming a monolithic structure. Cement to form the ring I6 is then cast on the base portion [4.

Closely surrounding the hearth ring [8 and extending above this ring and into the space between this ring and the ring I5, is a ring I8 formed of heat resisting metal, as for example and preferably, chromium steel, the ring I 8 being preferably about .035 inch in thickness, and forming with the hearth portion I5 an annular space I! about one inch in width.

The ring I 8 is shown as held in place by means of inner and outer series of clips l9 and 20, re spectively, each of which is of general U-shape as shown in Fig. 4 presenting a base portion 2| and upstanding legs 22 and 23, the latter being formed at its outer side with a downturned tongue 24 spaced therefrom. The clips l9 and 20 are interlocked at their tongues 24 with the ring at openings 25 in the lower edge portion of the latter as shown in Fig. 1, the clips [9 being embedded in the hearth ring I6, and preferably applied with the clips 20 and the ring [8 to the hearth ring M to the position shown before the cement forming the hearth portion I6 is filled in. The clips 20, which are located in the space I], serve to properly position the ring it relative to the hearth portion l5 in the assembling of the ring I8 with the base portion M.

In accordance with my invention the portion of the ring 3 which extends above the hearth section I6 is provided throughout its circumference with openings for the purpose hereinafter described. These openings may be of various shapes and arrangements. Preferably they are provided as shown in Figs. 1 to 6, inclusive, wherein five circumferential upper rows of circular closely spaced openings 26 and two lower circum ferential rows of relatively larger circular closely spaced openings 21 are provided. By way of example and preferab1y, the openings 26 are inch in diameter and the openings 2'! are inch in diameter, adjacent ones of the several rows of openings being spaced closely together, with the uppermost row of openings 26 closely adjacent the upper edge of the ring and the lower row, of openings 21 closely adjacent the upper surface of the hearth portion IS, the several rows of openings 26 and 21 extending entirely around the circumference of the ring l8.

Fig. 7 illustrates another arrangement of openings in the ring I8, in accordance with which the upper portion of the ring I8 is provided with a circumferential series of substantially vertical closely spaced slots 28 which by way of example may be inch Wide and inch long and below these slots are three circumferential rows of closely spaced openings the upper and lower ones of which and represented at 29 being, by way of example, inch in diameter and the intermediate row of openings representedat 30 of inch in diameter, the lower row of openings 29 extending close to the upper surface of the hearth portion I6.

Fig. 8 illustrates still another modification of the openings in the ring I8. In this arrangement the upper edge portion of the ring is provided with a circumferential series of vertical closely spaced slots 3I preferably about inch in width and louvered on the outer circumference of the ring, as represented at 32. Below the openings 3| are three circumferential rows of closely spaced openings 33, by way of example, '3 inch in diameter, the openings 33 of adjacent rows being closely spaced and the lower row extending close to the upper surface of the hearth portion I6.

The construction shown also comprises an oil,

burner assembly at the central opening in the hearth for projecting radially outwardly and against the ring member I8, atomized oil forthe combustion thereof, adjacent the side wall of the combustion chamber as hereinafter described, the flame produced being inthe form of a ring.

Any suitable construction of oil burner assemblymay be utilized with the hearth as for example the one shown, which, however, need not be described in detail as it forms no part of the present invention and is fully illustrated anddescribed in the pending application for U. S. Patent filed by Stanley Perry and myself, Serial No. 654,356, filed January 30,- 1933, it being sufiicient to state that the burner assembly shown comprises a rotary internal-fan-equippedmember 34 driven by a motor 35 and containing an annular series of vertical openings 36 through'which air is forced radially outwardly, together with a series of radially disposed pipes 31 located at certain of the openings 36 and opening at their inner ends through the side wall of a rotary oil cup 38 likewise driven by the motor 35 and through which pipes the oil discharges by centrifugal force,

against the ring I8, the burner assembly being so 7 the same as that shown and described in theabove referred to pending application; this construction involving, generally stated, a constantly-burning pilot 38 extending upwardly into the space I! and having an outlet 39 extending crosswise ofthis space to ignite a stream of gas discharged from a flare-jet burner (not shown) in the space I! to the rear of the-pilot 38 in Fig. 1, tangentially of this space and across thejet of flame from pilot 7 The gas is supplied .to the constantly-burning pilot 38 and the flare-jet-burnerthrough pipes 40 and 4|, respectively, communicating with a gasservice pipe 42 through mechanism represented generally at 43 and operating to control the sup- 7 plying of gas to the flare-jet-burner.

The following is a description of the operation of the combustion apparatus. The oil and air are discharged in a general horizontal direction from the oil and air distributing means of the burner above described, the oil discharging therefrom in atomized condition. The particles of atomized oil being of considerable weight tend to travel outwardly in a substantially horizontal direction, striking the ring I8 which in effect constitutes a primary impact surface, portions of the oil passing through the openings in the ring I 8. Assuming the igniter device to have been started in operation, the pilot flame produced thereby ignites the oil discharged through the openings in the ring I8 and also the oil adhering to the surface of this ring and within a few seconds the oil is ignited around the entire periphery of the ring, whereupon the ring I8 quickly becomes heated to an oil-vaporizing temperature with the result that the particles of oil thrown out by the distributor are not only further atomized by impact with the ring, .but are completely vaporized.

The construction is such that there is a tendency for a small percentage only of the air dis charged from the distributor head to be forced through the openings in the ring I8, the remainder of the air passing upwardly along the inner surface of the ring and rolling outwardly over the top thereof, a cushion of air being produced along. the inner surface of the ring I8. In the case of the oil, however, the action is quite different. The oil travels directly outwardly until it strikes the innersurface of the ring I8 Where it is further atomized and vaporized, assuming the ring I8 to have been heated by the igniter means as above described; and due to the fact that the oil is vaporized directly on the surface of the ring I8 a large proportion of the oil vapor thus produced passes through the openings in the ring while only a small proportion thereof follows up the inner surface of the ring I8 The air that passes through the openings in the ring I8 and expands as it leaves these openings quite possibly carries with it a portion, probably a large percentage, of the oil vapor produced, causing a very thorough mixture of the oil and vapor and a portion of the combustion air at this point While particles of oil thrown directly through the openings in the ring would likely, before becoming vaporized, strike the in ner surface of the wall portion !5 which forms a secondary impact surface particularly when the burner is cold, such particles would become thoroughly vaporized and mixed with air and vaporized oil passing through the openings in the ring I8 after the burner becomes heated.

The result of the filtering action 7 by the foraminated ring I8 is to produce in the annular space I! a mixture of oil and air which is rela-- tively rich in oil vapor but contains insufficient air for complete combustion. Partial combustion results, however, in the space I l but at a gradually increasing rate as the mixture travels upward in this zone inasmuch as most of the. oil vapor passes through the lower perforations in the ring I8 and the'percentage of air supplied to this space gradually increases due to the progressive increaseof therate of flow of the air through the upper perforations. vapor may be quickly consumed as it rises from this space of partial combustionand mingles with Thus the oil the air which rolls outwardly over the upper edge of the ring l8. Consequently there is little, if any, visible flame at the bottom of this space which constitutes a zone of partial combustion.

An advantage of the construction is that distinct separation is produced between the zone of combustion and the zone of non-combustion. No combustion occurs in the spacebetween distributor head and the ring l8. There is partial combustion in the space between the ring [8 and the outside refractory, secondary-impact-surface-forming, portion l and an intensely hot, but quiet, combustion directly above the space just referred to, the ring I8 thus in effect dividing the combustion chamber into three distinct zones.

Another advantage resulting from the use of the foraminated ring I8 is that the mixture of oil and air in passing through the openings in the ring loses velocity due to expansion of the air and therefore permits the mixture to be more. readily ignited.

As will be readily understood, the provision of the louvers 32 in the case of the modification of the ring i8 as shown in Fig. 8 causes the air and oil to discharge through the openings l3 in a tangential direction thereby tending to rotate the mixture and oil vapor beyond the ring which in some cases may be of advantage.

While the bottom of the space H is shown as disposed at a lower elevation than the upper surface of the hearth portion Hi, this is not essential to my invention, and as an example of a modification thereof reference is made to Fig. 5 wherein the space between the ring l8 and the hearth portion [5 is filled up to the level of the upper surface of the hearth portion [6, by a ring I 9 of refractory material, in which case the constantly-burning pilot 38 and the fiare-jet-burner above referred to are vertically elongated, as to cause their discharge orifices to extend above the upper surface of the ring l9 While I have illustrated and described certain constructions embodying my invention, I do not wish to be understood as intending to limit it thereto as the same may be variously modified and altered and the invention embodied in other forms of structure, without departing from the spirit thereof.

What I claim as new, and desire to secure by Letters Patent, is:

1. In oil combustion apparatus, the combination of a combustion chamber having a hearth and a surrounding side wall extending above said hearth, a ring of heat resisting material rising from the hearth and spaced from the surrounding side wall of said chamber, said ring having openings therethrough, and means at the center of the hearth for projecting air and finely divided oil directly against said ring, said openings extending over substantially the entire area of the portion of the ring impacted by the atomized oil.

2. In oil combustion apparatus, the combination of a combustionchamber having a hearth and a surrounding side wall extending above said hearth, a ring of heat resisting material extending above the upper surface of the hearth and spaced from the surrounding side wall of the chamber, said ring having openings therethrough disposed at different elevations and spaced apart about the circumference of the ring, and means at the center of the hearth for projecting air and finely divided oil directly against said ring, said openings extending over substantially the throughout the circumference of the ring, and means at the center of the hearth for projecting air and finely divided oil directly against said ring, said openings being distributed throughout substantially the full area of the ring.

4. In oil combustion apparatus, the combination of a combustion chamber having .a hearth of substantially flat construction with a side wall extending upwardly from the periphery thereof, a substantially vertical perforated wall structure extending above the upper surface of the hearth and spaced from said side wall, said perforated Wall structure having its openings spaced at different elevations throughout its height and at close intervals throughout its length, and means at the center of the hearth for projecting air and finely divided oil directly against said perforated wall structure, said perforated wall structure being of sufiicient height to intercept substantially all of the projected air and oil.

5. In oil combustion apparatus, the combination of a combustion chamber having a hearth of substantially flat construction with a side wall extending upwardly from the periphery thereof, a substantially vertical perforated wall structure extending above the upper surface of the hearth and spaced from said side wall, said perforated wall structure having its openings spaced at different elevations throughout its height and at close intervals throughout its length, and means at the center of the hearth for projecting air and finelydivided oil directly against said perforated wall structure, said perforated wall structure being of sufficient height to intercept substantially all of the projected air and oil and serving to permit the passage through the perforations of substantially .all of the oil vapors produced from the finely divided oil impacting against it while offering substantial resistance to the passage of air therethrough.

6. In oilcombustion apparatus, the combination of a combustion chamber having a hearth and a surrounding side Wall extending above said hearth, a ring of heat resisting material rising from the hearth and spaced from the surrounding side wall of said chamber, said ring having openings, means for spacing said ring from said side wall and anchoring said ring in position, and means at the center of the hearth for projecting air and finely divided oil directly against said ring.

'7. In oil combustion apparatus, the combination of a combustion chamber having a hearth and a surrounding side wall extending above said hearth, a ring of heat resisting material extending above the upper surface of the hearth and spaced from the surrounding side Wall of said chamber, said ring having openings therethrough disposed at different elevations above said hearth, and means at the center of the hearth for projecting air and finely divided oil directly against said ring, the entire area of the portion of the ring which is impacted by the atomized oil having openings therethrough.

8. In oil combustion apparatus, the combination of a combustion chamber having a hearth tion of a combustion chamber having a hearth.

and a surrounding side wall extending above said hearth, a ring of'heat resisting material extending-above the upper surface of the hearth and spaced from the surrounding side wall of said chamber, and means at the center of the hearth for projecting air and finely divided oil against said ring, said ring extending across the zone of projection of the oil and having openings of such size and arrangement as to permit of the passage therethrough of a large proportion of the oil in liquid or vapor form, but only a relatively small proportion, of the air which impacts said ring. 7

9; In oil combustion apparatus, the combinationof a combustion chamber having a hearth and a surrounding side Wall extending above said hearth, a ring of heat resisting material extending above the upper surface of the hearth and spaced from thesurrounding side wall of said chamber, said ring having openings disposed at different elevations above said hearth, the open ings of a row of lower elevation being of larger size than the openings: immediately thereabove,

and means at the center of the hearth for projecting air and finely divided oil directly against a portion of said ring having openings therethrough.

10. The combination of a combustion chamber having a hearth and-a surrounding side, wall extending above said hearth, a ring of heat resisting material extending above the upper surface of the hearth and spaced from the surorunding side wall of said chamber, said ring having at ieast four rows of openings at different elevations above the hearth, the openings of the two lower rows being of larger size than the openings of the rows thereabove, and means at the center of the hearth for projecting air and finely divided oil directly againsta portion of said ring having openings therethrough.

11. In oilcombustion apparatus, the combination of a combustion chamber having a hearth anda surrounding side wall extending above the hearth, a ring of heat resisting material extending above the upper surface of the hearth and spaced from the surrounding side wall of said chamber, said ring having openings at difierent elevations above the hearth and certain of which are in the form of slots, and means at the center of the hearth for projecting air and finely divided oil directly against a portion of said ring having openings therethrough.

12. In oil combustion apparatus, the combi nation of a combustion chamber having a hearth and a surrounding side wall extending above said hearth, a ring of heat resisting mate-rial extending above the upper surface of the hearth and spaced from the surrounding side wall of said chamber, said ring having openings at different elevations above the hearth and the upper ones of which are in the form of slots, and means at the center of the hearth for projecting air and finely divided oil directly against a portion of said ring having openings therethrough.

13. In oil combustion apparatus, the combinaand a surrounding side wall extending above said hearth, a ring of heat resisting material extending above the upper surface of the hearth and spaced from the surrounding side Wall of said chamber, said ring'having openings at different elevations above the hearth'and the upper ones of which are in the form of slots and the lower ones of which are of substantially circular shape, and means at the center of the hearth for projecting air and finely divided oil directly against a portion of said ring having openings therethrough.

14. In oil combustion apparatus, the combination of a combustion chamber having a hearth and a surrounding side wall extending above said hearth, a ring of heat resisting material extending above the upper surface of the hearth and spaced from the surrounding side wall of said chamber, said ring having openings at difierent elevations above the hearth, certain of said openings being in the form of slots having louvers at the outer surface of the ring, and means at the center of the hearth for projecting air and finely divided oil directly against a portion of said ring having openings therethrough. j

15. In .oil combustion apparatus, the combination of a combustion chamber having a hearth and a surrounding side wall extending above said hearth, a. ring of heat resisting material extending above the upper surface of the hearth and spaced from the surrounding side wall of the chamber, said ring having openings at different elevations above the hearth, theupper ones of said openings being in the form of slots and thelower ones of substantially'circular shape and substantially uniform in size, and means at the center of the hearth for projecting air and finely divided oil directly against a portion of said ring chamber, and means at the center of the hearth V for projecting air and finely divided oil directly against said ring, said ring having openings at difierent elevations above the hearth, certain of said openings being disposed over substantially the entire area of the portion of the ring impacted by the atomized oil and other openings below said portion.

17. In oil combustion apparatus, the combination of a combustion chamber having a hearth and a surrounding side wall extending above said hearth, a ring of heat resisting material extending above the upper surface of the hearth and spaced from the surrounding wall of said chamber and means at the center of the hearth for projecting air and finely divided oil directly against said ring, said ring having openings disposed at, above, and below, the portion of the ring impacted by the atomized oil.

OSCAR C. SCHROEDE'R. 

